The DEP says in a Tuesday release that Halliburton’s Homer City facility stored, treated and transported hydrochloric acid without obtaining proper permits between 1999 and 2011. That’s about 50 miles east of Pittsburgh.

DEP says the waste came from various natural gas well sites, and Halliburton transported it without proper trucking records and without using a licensed hazardous waste hauler. DEP says there’s no evidence the 255 violations caused actual harm to the public or the environment, and that the company signed a consent agreement on Feb. 7.

Halliburton, which is based in Houston, did not immediately respond to a request for comment.